Fluid controlled switch



May 26, 1936. G PRAY 2,041,726

FLUID CONTROLLED SWITCH Filed Aug. 17, 1932 2 Sheets-Sheet l Nl/EA/TOR f @xaq v May 26, 1936. G. E. PRAY,

FLUID CONTROLLED SWITCH I A 7" TOR/V8145 Patented May 26, 1936 FLUID CONTROLLED SWITCH E. Pray, Fort Monmouth,

Oceanport, N. J.

) George Application August 17, 1932, Serial No. 629,161

4 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3'10 0. G. 757) The invention described herein may be manu-'- iactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a means for controlling circuits and proposes a circuit controlling mgchanism operatively responsive to the flow of a uid. .7

,An' objector the invention is to provide a circuit control mechanism dependent essentially for its eflective operation upon the gradient factor, or change in the rate of fluid flow, and independently of static pressure.

The invention provides a protective device,

Such a device is applicable to cooling regardless of the nature of the circulating medium, such as used with high-power recshowing an alternative arrangement of switch contacts;

Fig. is a sectional elevation of a slight modification of the lever system based on the. form shown in Figures 1 to 3;

Fig. 6 is a sectional detail of the same form 5 shown in Fig. 5, wherein the circuit contacts are in open position;

Fig. 7 is a sectional elevation of a further modification, the contact elements being in circuit closed position; and e Fig. 8 is a partial section of the'form shown in Fig. 7, the contact elements being in open position.

.that the valve element may be sensitive to varia tions in the rate of fluid flow, independently oi fluid pressure within the system. 7

Moving in the direction indicated by the arwhich will operate between certain required lim- It will e und sto d that this inv nti n may 15 its 01 fluid or liquid flow, to control an electric be employed in connection with any fluid circucircuit when either-of these limits is reached. lating y i pective of the nature of the v A mechanism embodying the present invention, lating medium. while capable of sensitive adjustment, contem-r Refelring t0 the drawings. the circulating eplates as an important feature a period of delay um fl wing. f m a Source f pply n t A or retardation in the circuit controlling action hown) is fed through inlet p p i y nol the system. Thus, its circuit controlling action n cted to a asin f ed y w y of a p e is insensitive to slight variations of fluid flow. as a va casing. a hav web p ti ns land Moreover, avoidance of sparking in the switchintegralgwith e Casing. and serving to define log action is inherent in the present invention. 3 an orifice 5, which Orifice y take the f m f A'device constructed in accorda c with the a valve seat. A movable valve element or flow present invention 13 substantially a t ati i responsive device, hereinafter more fully deaetio and constantly resets itself, In t uit scribed, is disposed in operative relation with the controlling action, it is equally n it v t th r said orifice, which is open more or less during the of th desired erativ li it; of fl m normal operation of the mechanism to the end as tiner circuits, and radio vacuum tubes; or highpower radio transmitters, or to any cooling system employing aiiowwkliqufd whether I water, ,oil,

rows, the circulating medium flows by way of passage 6, througlnorifice 5 to passage 1, and 9 th'ence to d iscliare mo arwltn which the "alcihblir other similar medium/While partlcuiarly advantageous toru'se' as a flow relay in 40. connection with radio transmitter cooling sys- 45 of example in drawlnss. in

which:

J'lmliaaseciilonflelflationotonetothior embodimentoithelnmtimtheelectrlcalconw tactelementsbeing'shownincircuitclosinaposi- 5' Fig.4ishsectioualdetailoithesameiorm' tion;

FIgsJandliaresiniflarvimol-thesameiorm,

the contact elements ln-open circuitposition atuDDerlnd-lowerlimitnrupectively;

ing 2 communicates by means of suitable fluidtight connection. The device also comprises an upper chamber C having its base 8 provided with a threaded collar 10 for attachment to an interiorly threaded collar opening into valve casing 2 at Ill. The side walls II of chamber C are preferably formed oi glass or other transparent material to permit inspection of the mechanism housed in said chamber. The head I! or the chamber as here shown is composed of insulating material. The side walls are shown fitted into grooves I! in the head I: and base land the parts or the chamber are bolted in bled relation by means of tie rods it or, the like.

The circuit controlling mechanism comprises a system, including an electric switchlm meanaallhouaedinchambercinthepreaent instanoaandanelementetofluidflow ment being operatively coupled to the lever system by means of a connecting rod or plunger.

Referring more particularly to the embodiment shown in Figs. 1 to 5, the said lever system comprises a toggle arm I5 pivotally connected as at I6 to a stud I'I, rigidly secured to insulated head I2 as at I8. The lever system also includes another toggle arm I9 pivotally connected to arm I5 as at 20, said arm I8 being pivotally secured to fulcrum point 2| of a link 22, which is pivotally connected at 54 to a terminal stud 22, which stud is attached to insulated head I2 and also functions as an electric circuit connection. A portion of toggle arm I9 extends beyond the fulcrum point of connection and terminates in one contact element 23 of a switch means. The other contact element of said switch is formed as at 24 on a stud or terminal 25, which may be of any conducting material such as phosphor bronze, and is attached to the insulated head I2 as at 26. A simple series circuit is shown by way of example including a current source as 21, and comprising some form of signal which may be either an audible alarm or a visual indicator as 23, and circuit leads 23 and running to the aforesaid terminals.

The flow responsive means is shown in the form of a valve element 3I, provided with a stem or rod 32, to which it is suitably secured by a screw connection as at 33, and washers as at 34 may be employed, if desired,'to provide a means of extending or adjusting the length of said rod. Said rod is loosely coupled or linked to toggle arm I! of the lever system by a slotted connection as at 36, which serves as one method to permit a period of lost motion or retarded action in the response of the valve element 3I to flow of fluid. The rod 32 has operative movement in the manner of a piston rod through a perforation 31 in 'thebase 9.

In operation, the movable valve element 3I is so positioned as to be influenced by the flow impulse or gradient factor of the fluid medium, and independently of hydrostatic pressure inherent in the circulating system. Assuming for example in the usual case where a liquid is the circulatin: medium, the element 3| in its normal operation in accordance with the present invention is so placed as always to be suspended more or less out of contact with the seat or orifice 5, and, therefore, such hydrostatic pressure as may be inherent in the system is equalized or balanced on all sides oi said element 3 I. Thus said element is rmponsive only to the flow impulse of the cir 1 cuiating medium, and independently of pressure.

Referring to Figs. 1 to 3, the embodiment there shown will perform the functions of a protective device-which operates between certain required limits oi flow to interrupt an electrical circuit when either of these limits has been reached. Inl'ig. 1 the parts'pccupy a position .where the flowofiiuidisassumedtobeatadesiredmedium rate or value, in'which case the contact elements are in circuit closing position. Depending upon variations in the rate of now, if the flow increases .beyond a critical value, the parts takeupaposltionasshowninrigz andthe flow responsive element 3|, communicating movementthroush rod 32 to the leversystem, causes the contacts to open and break the circuit. Bimilsrly, if the flow falls below a critical value, the

parts again the contacts are broken to open the cirtakeupaposition asshowninl'lg.3,and'

- operatively disposed in the valve casing, said elewardly and communicating such movement through the rod 32 to the lever system.

The embodiment shown in Figs. 1 to 3 readily lends itself to an alternative form whereby the contacts are in open circuit position when the fluid flow is at a desired or normal level as will be clear by reference to Fig. 4. When the flow exceeds a desired level the toggle arm I9 of the lever system is carried upwardly by the movement of the flow responsive element 3| and its rod connection 32, and the circuit is completed through the movable contact at the end of arm I9 and the lower fixed contact element 38. when the flow drops below a desired level, the movement of the element 3| is downwardly, carrying toggle arm IS in the same direction through action ofthe connecting-rod and the movable contact element completes the circuit through upper fixed contact element 39.

A device embodying the present invention may be adapted to open the circuit only when the flow drops below a desired or critical value. A slightly modified form of device for this purpose is shown in Figs. 5 and 6, wherein the toggl arm I9 is provided with a projection 40 which co-operates with a recess 4| in arm I 5. Thus when the fluid flow is proceeding at its normal or desired value, the parts are in the position shown in Fig. 5, the upper movement of the lever system being limited by the locking action of projection 40 in shoulder recess ii, the contact elements being in circuit closing position. When the fluid flow falls below the desired value the downward movement of valve element 3I and its rod connection with the lever system opens the circuit controlling contacts.

In the modification shown in Figs. 7 and 8, the circuit controlling contacts close only when the flow exceeds a desired value, and open only when the flow decreases below the desired value. Means is also provided to produce a snap action of the switch means when the fluid responsive element goes above or below predetermined limits of movement. In said embodiment, the lever system comprises a main arm I9a having one portion coupled as in the other forms to rod 32 and having the same slotted link coupling with said rod to provide a period of lost motion or retarded action as in other forms. Arm Ila is pivotally connected at fulcrum point 42 to stud 33, which stud is of electrically conductive material and is secured to the insulated head in electrical communication with terminal 44. The

arm I which is also a conductor of electricity has an extension terminating in contact element 23 of the switch means. The other contact element 24 of the switch is formed on stud 25, attached to the insulated head l2 at 28 and protrudes above the head to serve as a terminal connection. The structure Just described constitutes a switch means which functions in the same manner as in other forms of the device. The lever arm I30 has a member 43 extending downwardly from the dead center or fulcrum point 32. To provide for snap action, means such as spring 43 is attached at "to the member 43 and at its opposite end is attached to adjusting plate ll, adjustably secured to stud 43 by slotted connection 30. A lug 33 secured to said plate 43 operates with adjusting screw 3| to provide for adjustment of the tension of spring 43. Additional stop shoulders 32 and 33 are provided on either side of stud 33 to limit the movement ofleverarm m when thecircuit contacts 1' either in open or closed position. In operation, the contacts Band 24 are in circuit closing position when the flow exceeds a desired or critical value, as shown in Fig. 7. When the flow falls below the desired value, the contacts are in open position breaking the circuit, as shown in Fig. 8. When the flow is proceeding at a correct or desired value, the parts are in the position indicated by the dotted lines in Fig. 8, and the contacts are also open under this condition.

Changes and modifications are contemplated within the scope of the appended claims:

I claim:

1. An electric switch circuit control mechanism, comprising an electric switch and a lever system for actuating the switch; means responsive to fluid flow comprising a valve structure and including interior web portions formed to define an orifice for directing the flow of a circulating fluid; a movable element of said valve having a tapered formation; and means for locating said element in normal operative relation to said orifice whereby said element is supported and operated by the flow of fluid through said orifice, said means including an adjustable coupling for coordinating said element and lever system to control the operation of said system in response to maximum and minimum predetermined variations in the rate of fluid flow.

2. An electric switch circuit controlling mechanism of the character described, comprising an electric switch; a lever system for actuating the switch; means comprising an element normally supported by flow of a circulating fluid and responsive to variations of flow for controlling the operation of the lever system at maximum and minimum predetermined flow levels; and means for coupling said element and lever system, and including contact elements operative with the switch, whereby said switch is thrown into circuit opening position when the rate of flow is either above or below a desired level.

3. An electric switch particularly adapted to be chamber comprising a transparent wall and an insulated cover, said lever system supported from said insulated cover and electrical contacts associated with said lever system, a movable rod cooperating with said lever system and said movable element for controlling the opening and closingof said contacts when the rate of fluid flow is either above or below a desired level.

4. An electric switch particularly adapted to be controlled by a fluid comprising a lever system for actuating said switch, means responsive to fluid flow comprising a valve structure and including interior web portions formed to define an orifice for directing the flow of a circulating fluid, a movable element for said valve, means for locating said element in normal operative suspension in said fluid and in normal operative relation to said orifice so that said movable element is sensitive to variations in the rate of fluid flow and independent of fluid pressure within said system, an upper chamber located above said orifice, said chamber comprising a transparent wall and an insulated cover secured to said valve structure by a plurality of tie rods, said lever system supported from said insulated cover and electrical contacts associated with said lever system, a movable rod co-operating with said lever system and said movable element for controlling the opening and closing of said contacts when the rate of fluid flow is either above or below a desired level.

GEORGE E. PRAY. 

